Perhaps I oriented something incorrectly?? the + and - DC inputs? The MOSFETS? The voltage references?

I don't think that there were any errors on Kari's L/R preamp boards (unlike the 2 on the power supply) but I could be wrong.

edit- the power supplies are working, +60V and -8V DC. The 22.1 ohm resistors are under the board so you don't see them. I have no grounds connected to the inputs and outputs, yet (no signals going in or out at this point) figured that the DC power supply ground would be sufficient to get it up and running, and that one is connected.

Pretty sight Do check your wiring again! As far as I know, the boards are supposed to work. Did you swap in/out wires with the ground wires or something like that? I just happened to do that on one channel of a preamp Take a really close look at all your wiring. I just built the Twisted BosoZ, which is based on Kari's schematic, and it works (wonders!) Good luck

Originally posted by steenoe Pretty sight Do check your wiring again! As far as I know, the boards are supposed to work. Did you swap in/out wires with the ground wires or something like that? I just happened to do that on one channel of a preamp Take a really close look at all your wiring. I just built the Twisted BosoZ, which is based on Kari's schematic, and it works (wonders!) Good luck

Steen

Yeah, I checked the wiring. Hmm.....is the silkscreen ok on those boards? anything shown backwards?

I'll take some DC measurements and post results if this can't be solved asap.

Yep, I quote: Important! The diodes on the positive side has a silkscreen error! Just turn the diodes 180degrees and you should be fine.
Also D9 and D10 are connected wrong. Please connect them as the picture here:
I just took a pic of the pic from Kari's homepage Hope you can see it Luckily enough, I did print it out, when the homepage was still running Here you go Hope this is the answer!

Steen
Sorry if this is the problem, I took it for granted, that you knew about it!

Originally posted by lgreen ***
I don't think that there were any errors on Kari's L/R preamp boards (unlike the 2 on the power supply) but I could be wrong.

edit- the power supplies are working, +60V and -8V DC. The 22.1 ohm resistors are under the board so you don't see them. I have no grounds connected to the inputs and outputs, yet (no signals going in or out at this point) figured that the DC power supply ground would be sufficient to get it up and running, and that one is connected.

anyone?

I wish!!!! actually I caught the errors in the power supplies and fixed them as per everyone's posts. So its not that....

Darn Well, I have a pair of Kari's boards too I will try to see if I can solder them up, next week and find the faults, if there are any! At this point I cant offer you better than that I recommend that you check the wiring again, though Could someone please give a link to a working preamp of Kari's?? Please come forward if you know of one!

Maybe the fact that Colombo is not delivering parts from the group buy is not as bad. Otherwise we all will be pulling our hairs.
Sorry Lgreen
I still hope for the parts so I could join you in finding the problem. This whole thing was a problem - long wait for the boards, mistake on boards, no parts... Unfortunate. And I have 6 boards!!!